THE BA CILL US OF OLA NDEBS. 319 



on media that can be kept at higher temperature, 

 though it does grow on this media at room temperature 

 without causing liquefaction. 



Its growth on blood-serum is seen in the form of a 

 moist, opaque, slimy layer, inclining to a yellowish or 

 dirty, brownish-yellow tinge. It does not liquefy the 

 serum. 



' On potato its growth is moderately rapid, appearing 

 at the end of from twenty-four to thirty-six hours at 

 37° C as a moist, amber-yellow, transparent deposit 

 which becomes deeper in color and denser in consistence 

 as growth progresses. It finally takes on a reddish- 

 brown color, and the potato about it becomes darkened. 



In bouillon it causes diffuse clouding, with ultimately 

 the formation of a more or less tenacious or ropy sedi- 

 ment. 



In milk to which a little litmus has been added it 

 causes the blue color to become red or reddish in from 

 four to five days, and quite red after two weeks at 37° C 

 At the same time the milk is separated into a firm clot 

 of casein and clear whey. 



Its reactions to heat are very interesting — at 42° C. 

 it will often grow for tw^enty days or more. It will 

 not grow at 43° C, and is killed by exposure to this 

 temperature for forty-eight hours. It is killed in five 

 hours when exposed to 50° C, and in five minutes by 

 55° C. 



It grows both with and without oxygen; it is there- 

 fore frtcuftafife as regards its relation to this gas. 



On cover-slips it stains readily with all the basic 

 aniline dyes, and, as a rule, as stated, presents conspic- 

 uous irregularities in the way that it takes up the dyes, 

 being usually marked by deeply stained areas that alter- 



